u-joints keep breaking.

[eightyone]

i have a k5, 4 inch lift, 14 bolt full floater, np208, sm465. with my drive shaft lengthend an inch. and the rear u joints keep breaking. the top and bottom ones. whats the deal?

 

[Jonny-K5]

what are your U-Joint angles? where are they breaking?

 

[big83chevy4x4]

it should have 1350 ujoints. its very hard to break them in torque, most likely they are binding.
or are they wearing out?

 

[reeser]

if you're using the 'conversion' joint, there's your problem, upgrade to a real 1350 and make sure your straps are tight.

 

[Hossbaby50]

A 4 speed truck should have true 1350 ujoints in it from the factory. Under what conditions do you normally break the joints?

I am running a 700R4/208 with driveshaft out of a 465 truck with 4" lift. The driveshaft isn't at the greatest angles but it works fine. It will bind at full axle droop though. I had to build a limiting setup to stop the axles downtravel.

How did you achieve the 4" lift? Lift blocks, springs, shackle flip, ?

Harley

 

[eightyone]

i got 4 inch blocks int he rear, the joints keep breaking at any time, wen im driving down the street, wheelin, accelerating...always. it has a conversion joint.

 

[Hossbaby50]

The block probably isn't helping anything out. It allow the axle to wrap the springs easier and this will bind the ujoint if the axlewrap is bad enough. The conversion joint could also be part of the problem.

Check the angles on the ujoints. They should be pretty close to each other.

Are you greasing the ujoint fully before install? Some ujoints come greased some don't.

Harley